1. Field of the Invention
The present invention relates to a semiconductor integrated pressure transducer and a method for fabricating such a transducer.
2. Description of the Prior Art
It is known in the art to integrate pressure transducers with Metal Oxide Silicon (MOS) circuitry, in particular, piezo resistive pressure sensitive devices are known, but have not been adopted because of the lack of sufficient amplitude of signal for ready detection and processing.
A further type of semiconductor integrated pressure transducer is disclosed in European Patent No. EP-B-0049344. The transducer disclosed in No. EP-B-0049344 is a capacitive pressure transducer characterized in that it comprises an electrically conductive diaphragm of semiconductor material surrounded and supported by a body of semiconductor material, a perforated electrically conductive membrane so supported by the body of semiconductor material that it is spaced from the diaphragm to form a hollow between the membrane and the diaphragm, the diaphragm and the membrane respectively serving as the movable plate and the fixed plate of a capacitor, the capacitance of which varies in dependence on the pressures on opposite sides of the diaphragm.